It has become increasingly desirable to improve the overall system design and operation of gas turbines. In a system having a typical gas turbine engine, electrical power is extracted via an electrical generator to supply electrical power to control systems, actuators, weapons systems, climate control systems, and the like. Electrical storage, such as a battery, is typically provided to operate such systems when the gas turbine engine is not running or to provide power for starting the gas turbine engine. In some known gas turbine engines, the gas turbine engine includes a high pressure shaft and a lower pressure shaft, and the electrical generator is coupled to one of the high and low pressure shafts.
The electrical generator commonly generates thermal energy when in operation. It is important to actively cool the electrical generator during operation in order to ensure proper operation as well as extend the lifespan of the generator. This is commonly accomplished through the use of a fan attached to the generator shaft. The fan adds undesirable weight and complexity to the generator. In addition, when the generator is operating at altitude in an aircraft there becomes a reduction in air density. This results in a reduction in air-flow, which in turn reduces cooling. Increasing fan velocity may be utilized to partially address these losses, but is not always efficient or practical.
Overcoming these concerns would be desirable, could improve generator efficiency, and could save the industry substantial resources.